Mechanical separation of rubber from rubber-bearing plants.



E. DELAFOND.

MECHANICAL SEPARATION OI' RUBBER FROM RUBBER BEARING PLANTS.

APPLICATION FILED JAN.23, 1905.

up... 114111. I

'UNITED ATENT OFFICE.

icLiAs oELAroND, or mexico, Mexico.

Specification of Letters Patent.

Patented May 4, 1909.

Application nled January 23, 1905. Serial No. 242,365.

To all whom it may concern.'

'Beuit known that I, ELIAS DELAFOND, a citizen of the United States of America, residing at Mexico city', in the Republic of Mexico, have invented certain new and uscfu'l Improvements in Mechanical Separation of Rubber from Rubber-Bearing Plants; and I do hereby declare the following to be a full, clear, and-exact description of the invention, suoli vas Will enable others skilled in the art to which it appertain's to make .and use the same, reference being had to the accompanying drawings, and to letters of reference' marked thereon, which form a part of this specification.

This invention has relation to the extraction of 'rubber from so-called rubber )lants other than those from which the rub er is obtained by tapping. There is quite a large Variety of such plants having the character of shrubs, vines and bushes or small trees, from which the rubber has heretofore been extracted by chemical processes only, Which arenot yonly quite expensive as regards the costof chemicals, but also involve a great deal of time and labor. Furthermore, the product of these processes can, as a rule, not

c vulcanized Without further special treatment, owing to the presence of resinous or guinimy and fatty resinous constituents which are not vulcanizable. This is more especially true of rubber obtained from the Parthen'ium Argentaftum, which contains .a high lpercenta'e of non-vulcanizable substances referred to.

I have discovered that vulcanizable rubber can be AObtained from all rubber bearing plants except perhaps from the Partheniu'm A?" cnta'tum, by urely mechanical means, an that the rub er obtained from the Parthem'um Argentatum can be treated in a very sim le manner so that it will readily vulcaniz'e,"and that the rubber obtained by inechanical means from any rubber bearing plant can by a simple further treatment be reed from foreign constituents in a Very simple manner if it is desired to obtain what I may term anabslutely pure. product, or so called"virgin rubber for special purposes..

In carrying out my invention in so far as it relates to the mechanical extraction, or perhaps more properly, the mechanical se aration of the rubber vesicles from the igneous cellulose and other foreign constituents, l employ mechanism which, in its general character, is well known, though the product resulting from the operation of the mechanism differs radically from the products usually obtained therewith. But that my invention may be fully understood, I will describe the same in detail, reference being had to the 4accompanying drawing,

which illustrates a suitable apparatus for effecting the mechanical separation of rubber from rubber bearing plants by a vertical longitudinal section.

In carrying out my invention the rubber plants are first ground or otherwise sufficiently reduced by any suitable mechanical appliances to adapt the reduced material to be fed toy stones such as are commonly used in flour mills, to be reduced to flour, which is then fed to the same, or preferably to another similar mill, and preferably after being heated to some extent. This causes the rubber vesicles to dilate or .expand and become quite elastic, While the greater part lof the non-vulcanizable resins and gums are melted and absorbed by the ligneous and cellulose flour, and in this manner separated from the rubber vesicles. As the material passes between the stones the expanded rubber vesicles are, subjected tc pressure, friction and rolling, and not to a grinding action., as might be su posed, the vesicles being agglomerated andP rolled, and are discharged from the stones in the form of small cylinders, or as I term them, sausages, While the ligneous and cellulose constituents charged with the non-vulcanizable resinous and gumlny constituents are separated, the matcrial being discharged onto a Yscreen which retains the rubber cylinders only.

Although I prefer to heat the pulverulent material before feeding it to the stones, as it -expedites the agglomeration of the rubber vesicles, this is not absolutely necessary.

The se )aration of the ligneous and nonvulcaniza le resinousand gummy constituents from the rubber may be rendered more perfect and more expeditious by chilling and Washinghwhereby said non-vulcanizable resionous and gummy constituents become hard and more firmly attached to the ligneous-constituentsrlhis is accomplished by simply feeding Coldwater to the mill stones durlng their operation on the material. In

this manner I obtain a -final merchantable roduct which can be readily vulcanized, from all rubber bearing plants I have so far used in my process except the Pa-rtzenium readily vulcanizable I treat it with a novel solvent, namely with fusel oil from the distilleries by kneading the rubber with the oil, .I am thus enabled to readily eliminate the excess of the non-vulcanizable resinous and gurnmy constituents, having found that fusel oil answered the purpose better than of the other many solvents I have tried. I have, however, also discovered that the rubber obtained mechanically as described from the Parthe'nium Argentan/,m can be vulcanized by increasing the percentage of sulfur by about 25% and by vulcanizing under a higher pressure, say four-an'd-a half atmospheres, instead of two, as usual. If itis desired to obtain a pure final product, whatI may term a virgin rubber, I treat the rubber product obtained mechanically as described with a mixture of fusel oil and of an alcoholic solution of a caustic alkali, as soda or potash, preferably soda, by triturating or kneading, for the purpose of removing the small remaining quantity of ligneous cellulose and non-vulcanizable resinous and gummy constituents. The fusel oil has a very peculiar action on the rubber, irrespective of its action as a powerful solvent of the non-vulcanizable resinous and gmmy constituents, in that it protects the rubber, in a great measure, against becoming hard and brittle, while the alcoholic alkali vsolution -saponifies the fatty constituents or fatty reslns.

In practice I use about one liter either of fusel oil per kilo of rubber, when this alone is used or mixed withl the alcoholic solution of a caustic alkali, the-proportion of the latter in the solution varying in accordance with the.

proportion of fatty resins remaining in the mechanically obtained rubber. Of course it is well understood that both the alcohol and fusel oil can readily be recovered by well known means and used repeatedly.

Referring now to the accompanying drawingfi,ndicates the frame of the machine provided With bearings b for the mill driving shaft s on which the revoluble stone S is secured and coperates with the stationary stone S. The shaft s carries the usual fast and loose belt pulleys p, p', and three sprocket wheels w, w', tu2 of successively de creasing diameter adapted to be chained to sprocket wheels w3, w, L05 of successively increasing diameter and secured to a transmitting shaft s, for the purpose of regulating the speed thereof, any suitable and well known means being also provided for adjusting the shaft s longitudinally to regulate the distance between the grinding faces of the mill stones S and S.

In the inner end of the driving shaft s is formed a socket s2 which'serves as a bearing for one end of the shaft s3 of a, preferably, conical screw-conveyer c, whose op osite end revolves in a bearing on a feed opper h, which i'ncloses the outer end of the conveyer, that portion thereof between said hopper and the stationary stone S being inclosed by a jacketed casing c2 having steam supply pipe p2 and a suitable steam trap t. The smaller end c of the conveyer c, extends through the stationary stone to feed the material to a central cavity between the stones, as usual.

To the outer end of the conveyer shaft is secured a sprocket wheel w6 chained to a like wheel w7 on the transmission shaft s.

From the description of the machine its operation will be readily understood, the material being discharged into a discharge hopper h and from thence onto a screen, not shown, while water is admitted to the grinding faces of the stones through a pipe p3.'

As the finely ground heated material is fed to the stones the rubber vesicles are agglomerated by friction and pressure and rolled into small cylinders, in which form they leave the stones, while the ligneous and cellulose constituents together. with the greater portion of the non-vulcanizable constituents ereinabove referred to are separated and Y washed away by the water.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent, is

The method of extracting rubber from rubber bearing plants, which comprises grinding the entire dry or green plants, feeding the ground mass to grinding stones to agglomerate the rubber vesicles, and heating the ground mass as it is being fed to the stones to permit the ligneous substances to absorb the resins and supplying cold water to the heated ground mass during agglomeration to suddenly harden the resin soaked ligneous substances and assist their comminution, grinding and separating them from the agglomerated rubber vesicles.v

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

ELIAS DELAFOND.

Witnesses:

. JOHN H. MOORE,

GRAHAM M. KER. 

